Inertial Measurement Units (IMUs) measure the motion of a body in six degrees of freedom using a set of gyroscopes and accelerometers with input axes aligned with three orthogonal axes. The instruments are typically self-contained devices with electronics and a package. Each instrument is tested prior to use in an IMU. The instruments are then assembled with the proper alignment onto a stable member of the system. With expensive high performance IMUs, the cost associated with this approach may be acceptable. However, with miniature, low cost instruments having correspondingly lower performance, the approach is not cost effective. The solution is to make use of integrating technologies such as Microelectromechanical Systems (MEMS) to fabricate all the instruments at the same time on one substrate to produce an IMU in one package. The testing will be done at the IMU level. In addition to cost and size reduction, integration provides benefits that improve performance. The practicality of integration, though, depends on the proper choice of instrument designs.